“未捕获的类型错误：无法在 Websocket Angular JS 上读取未定义的属性‘延迟’”

Posted 2023-02-16

【中文标题】“未捕获的类型错误：无法在 Websocket Angular JS 上读取未定义的属性‘延迟’”

【英文标题】："Uncaught TypeError: Cannot read property 'defer' of undefined at Websocket Angular JS"

【发布时间】：2017-09-24 23:45:11

【问题描述】：

我对网络技术很陌生，我从互联网上获得了一些代码片段，并以某种方式设法形成了这段代码。

我必须通过 API 从 websocket 将数据获取到用 angularjs 开发的 web 应用程序。

这里是代码，

 angular.module("MyApp")
        .service("myService", function ($rootScope, $q) 
            return 
                _prevTransmittingStatus: null,
                transmitting: false,
                _transmissionStatus: function () ,
                socket: null,
                socket_msg_id: 0,
                socket_history: ,
                url: "ws://localhost:4848/app/",
                setOnTransmissionStatus: function (callback) 
                    var self = this;
                    this._transmissionStatus = function () 
                        if (self.transmitting != self._prevTransmittingStatus) 
                            self._prevTransmittingStatus = self.transmitting
                            callback(self.transmitting)
                         else 
                    
                ,

                connect: function (callback) 

                    var deferred = $q.defer();
                    var promise = deferred.promise;

                    var self = this
                    this.transmitting = true;
                    this._transmissionStatus();
                    this.socket = new WebSocket(this.url);
                    this.socket.addEventListener('open', function (e) 
                        self.transmitting = false;
                        self._transmissionStatus();
                        deferred.resolve("connected")
                    );
                    this.socket.addEventListener('message', function (e) 
                        var asJson = angular.fromJson(e.data)                   
                        var replyId = asJson.id;
                        var histItem = self.socket_history[replyId]
                        self.transmitting = false;
                        self._transmissionStatus();
                        if (angular.isUndefined(asJson.error)) 
                            $rootScope.$apply(histItem.defer.resolve(asJson.result)) 

                         else 
                            **GetActiveDoc();/*how to call this */**
                            console.log("---rejected-----");
                            $rootScope.$apply(histItem.defer.reject(asJson.error)) 
                        

                    );
                    return promise;
                ,
                disconnect: function () 
                    this.socket.close();
                    this.transmitting = false;
                    this._transmissionStatus();
                    return this;
                ,
                send: function (msg, scope, callback, onerror) 
                    console.info("SEND:", msg)
                    var _this = this;
                    this.transmitting = true;
                    this._transmissionStatus();
                    if (!this.socket) 
                        return this.connect().then(
                            function (histItem) 
                                console.log("CONNECT SUCCESS", histItem)


                            ,
                            function (histItem) 
                                console.log("CONNECT ERROR", histItem)
                            

                        ).then(function () 
                            return _this.send(msg, scope);
                        )
                     else if (this.socket) 
                        console.log("socket is open")
                        var deferred = $q.defer();
                        var promise = deferred.promise;
                        msg.id = this.socket_msg_id;
                        this.socket_history[msg.id] = 
                            id: msg.id,
                            defer: deferred,
                            scope: scope,
                            msg: msg
                        ;
                        this.socket_msg_id++
                        this.socket.send(angular.toJson(msg))
                        return promise
                    
                ,
                isConnected: function () 
                    return this.socket ? true : false;
                
            
        );

我收到错误"Uncaught TypeError: Cannot read property 'defer' of undefined at Websocket" 只是在我第一次打开我的网络应用程序时。 谁能解释一下如何解决这个问题。

【参考方案1】：

自己解决了，只是添加/修改代码如下，

 if(replyId >= 0)
       $rootScope.$apply(histItem.defer.resolve(asJson.result))